Electrolytic capacitors are increasingly being used in the design of circuits due to their volumetric efficiency, reliability, and process compatibility. Electrolytic capacitors typically have a larger capacitance per unit volume than certain other types of capacitors, making them valuable in relatively high-current and low-frequency electrical circuits. One type of capacitor that has been developed is a wet electrolytic capacitor that includes an anode, a cathode current collector (e.g., aluminum can), and a liquid electrolyte. Liquid electrolytes are advantageous due to the potential to reach high ionic conductivity. However, such an electrolyte has its drawbacks as well. For example, a separator material (e.g., fabric or paper) is often required not only to retain the liquid electrolyte between the anode and cathode, but also to maintain a constant distance between the electrodes. This is particular important for high voltage and high reliability capacitors. Unfortunately, although the liquid electrolyte itself has a comparatively high ionic conductivity, the combination of the liquid electrolyte and separator material has a higher electrical resistance. The addition of a separator may also decrease the energy density of the capacitor. Furthermore, the liquid electrolyte is often apt to leak from the capacitor, which can lead to various problems, including a difficulty in mounting to electrical devices.
As such, a need currently exists for an improved electrolytic capacitor that contains a liquid electrolyte.